Researchers from China's Harbin Institute of Technology and University of Electronic Science and Technology of China have proposed a facile and universal platform to fabricate integrated spectrometers with solution-processable semiconductors by involving the conjugated mode of the bound states in the continuum (conjugated-BIC) photonics.
Acquiring real-time spectral information in point-of-care diagnosis, internet-of-thing, and other lab-on-chip applications requires spectrometers with hetero-integration capability and miniaturized form. Compared to conventional semiconductors integrated by heteroepitaxy, solution-processable semiconductors provide a much-flexible integration platform due to their solution-processability, and, therefore, more suitable for multi-material integrated systems. However, solution-processable semiconductors are usually incompatible with micro-fabrication processes, making them impractical for use in various applications.
Exploiting the conjugated-BIC photonics, which remains unexplored in conventional lasing studies, renders the broadband photodiodes with ultra-narrowband detection ability, detection wavelength tunability, and on-chip integration ability while ensuring the device performance. Spectrometers based on these ultra-narrowband photodiode arrays exhibit high spectral resolution and wide/tunable spectral bandwidth.
The fabrication processes are compatible with solution-processable semiconductors photodiodes like perovskites and quantum dots, which can be potentially extended to conventional semiconductors. Signals from the spectrometers directly constitute the incident spectra without being computation-intensive, latency-sensitive, and error-intolerant. As an example, the integrated spectrometers based on perovskite photodiodes are capable of realizing narrowband/broadband light reconstruction and in-situ hyperspectral imaging. The reported platform provides insight into constructing integrated spectrometers with multi-material integrated system.
“Exploring the conjugated-BIC is unconventional when compared with those popular BIC lasing studies. Through the theoretical study, we find that the conjugated-BIC experiences high leakage and decent Q while it can be easily excited and coupled. Considering that the conjugated-BIC photonics can be facily fabricated and their resonant wavelengths can be effectively tuned, we anticipate that the conjugated-BIC is very suitable for wavelength-resolved photodetection applications”, explained the team. “Solving the problems in fabricating perovskite photodiode arrays and integrating them with the conjugated-BIC photonics by micro-fabrication processes are also important since the materials and device interfaces of the devices can be easily destroyed during the processes by solvents and heat. We also believe that the photonics-optoelectronics integration platform we proposed can provide insight into broadening the functionalities and applications of the emerging solution-processable semiconductors like perovskites.”